We'll pardon ya, since Olives are one of the hardest families to differentiate to the species level, lol. The short answer, in this case, is that the shell is too "fat" to be either of the large species from Florida. Even though some of them can be extremely variable in color and pattern, there are a few standard forms that are most common, some with separated names. Color and pattern can be a good starting point for an ID, but you have to compare the spire height, length to width ratio, and columella color and shape to verify your guess. The width of the aperture can also be a clue, as can the shape and construction of the earliest whorls of the spire, the protoconch. For a couple of the Indo-Pacific species, the easiest way to separate them is by the lip: in one species the lip edge is rounded and smooth, while in the other species it's almost sharp.
Since Richard's olive is fat, with a dark gray tented pattern showing two distinct bands, with the tiny bit of the lip showing in the second pic above appearing orange or reddish, and since I know that is one of the most common forms of Oliva reticulata, that let's me make an educated guess at its ID.
Here are the two large Florida species. Notice the difference in overall shape:
http://www.gastropods.com/2/Shell_182.shtml
http://www.gastropods.com/3/Shell_1203.shtml
Oliva sayana is way more elongated and cylindrical, while Oliva reticularis is more oval, with a much taller spire. The latter also lacks the distinct banding.
Cheers,
Don